P0638 on Jeep
Throttle Actuator Control Range/Performance Bank 1
P0638 on Jeep vehicles indicates throttle actuator control range/performance bank 1. Au7o has documented this code across 1 Jeep model — most commonly on Grand Cherokee. This code means the engine computer detected that the electronic throttle plate (Bank 1) is not opening or closing to the position it commanded. The PCM monitors throttle actuator position against the desired angle and sets this code when they disagree. This can trigger reduced-power 'limp' mode, hesitation, or unexpected changes in engine response, which makes it a safety-relevant fault. Typical repair costs on Jeep range from $150 to $650, depending on the specific model and root cause.
Common Causes of P0638
- •Dirty or carbon-clogged throttle body
- •Faulty throttle actuator motor
- •Failed throttle position sensor
- •Corroded or loose throttle body connector
- •Wiring faults in the throttle control circuit
- •Mechanical binding of the throttle plate
- •PCM fault
P0638 on Jeep by Model
Jeep Grand Cherokee(1 issue)
- Electronic Throttle Control (ETC) Warning Light and Throttle Body Failure Causing Limp Mode (3.6L Pentastar)2011-2022
The amber lightning-bolt-in-parentheses 'Electronic Throttle Control' (ETC) warning is one of the most frequently reported faults on Pentastar-era Grand Cherokees. A contaminated or worn electronic throttle body, a failing throttle position sensor, or a corroded throttle-body connector causes the PCM to drop the engine into a reduced-power 'limp' state, with sudden loss of acceleration, surging, rough idle, or stalling. Owners frequently report the light clearing temporarily after a restart, then returning. Some cases are actually triggered by an out-of-range oil-temperature sensor or a stuck thermostat rather than the throttle body itself, so diagnosis before parts replacement is important.
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View P0638 across all makes →Frequently Asked Questions
What does P0638 mean on Jeep?▼
P0638 stands for "Throttle Actuator Control Range/Performance Bank 1." This code means the engine computer detected that the electronic throttle plate (Bank 1) is not opening or closing to the position it commanded. The PCM monitors throttle actuator position against the desired angle and sets this code when they disagree. This can trigger reduced-power 'limp' mode, hesitation, or unexpected changes in engine response, which makes it a safety-relevant fault. On Jeep specifically, this code is documented across 1 model.
What causes P0638 on Jeep vehicles?▼
Common causes on Jeep: Dirty or carbon-clogged throttle body, Faulty throttle actuator motor, Failed throttle position sensor, Corroded or loose throttle body connector, Wiring faults in the throttle control circuit. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0638 on a Jeep?▼
Repair costs on Jeep range from $150 to $650, depending on the specific model and root cause.
Which Jeep models have P0638 documented?▼
Au7o has documented P0638 on 1 Jeep model: Grand Cherokee.